pentad

[ pen-tad ]
/ ˈpɛn tæd /

noun

a period of five years.
a group of five.
the number five.
Chemistry. a pentavalent element or group.
Climatology. a period of five consecutive days.

Origin of pentad

1645–55; < Greek pentad- (stem of pentás) group of five. See pent(a)-, -ad1

Example sentences from the Web for pentad

British Dictionary definitions for pentad

pentad
/ (ˈpɛntæd) /

noun

a group or series of five
the number or sum of five
a period of five years
chem a pentavalent element, atom, or radical
meteorol a period of five days

Word Origin for pentad

C17: from Greek pentas group of five